Novel SJ-LDMOS on SOI with Step Doping Surface-Implanted Layer

A super-junction (SJ) SOI-LDMOS with step doping surface-implanted n-type layer is proposed and optimized which allows high breakdown voltage (BV) and low on-resistance (R_on). The proposed structure overcomes the field effect action in conventional SJ SOI-LDMOS devices thus achieving the charge compensation between the n and p pillars as well as a near uniform electric field distribution in the drift region in the off-state. The surface-implanted layer also provides a low current path in the on-state. The simulation results show that an increase in the off-state BV by 55% and a reduction of the specific on-resistance by 37.4% are obtained for the proposed device when compared with those of the conventional one.